This invention is directed to a multi-sonic sensor and more particularly a multi-sonic sensor used for high precision steering sensing combined with precision elevation sensing for machine control.
Current sonic sensors which measure elevation with multiple sensing elements for machine control systems have very coarse steering measurement capability when using a string line reference. The steering accuracy is usually in the low centimeters or even in the low inches which is not adequate for automating the machine control steering. This accuracy is typically only good enough to provide a visual indication to a driver of the direction a vehicle should be manually steered.
In addition, maintaining a constant elevation while measuring steering on a string line is problematic when the position changes and measuring elevation while finding a sufficient steering reference for machine control is also problematic. Further, a problem with current sensors is removing minor surface flaws from the elevation measurement.
With respect to temperature compensation, current schemes measure temperature once and then sample each individual sonic sensor which compensates the speed of the sonic pulses per the temperature variation from the single temperature measurement taken at the beginning of cycle. The separation in time between the temperature measurement and the subsequent sonic sensor samples allows for quick temperature changes which creates lagging temperature compensation of the last sampled sonic sensor and are increasingly more susceptible to temperature drift compensation error.
Temperature bails, which compensate for the change in temperature, are not calibrated for differences between sensors in a multi-sonic sensor. The bails also can be easily damaged or lost and can also cause damage to the sensor when the bail is damaged.
Finally, multi-sonic sensors typically are removed from a machine at the end of a work day to guard against theft and/or malicious acts that cause damage to the sensor. As such, sensors are securely attached to a machine which does not allow for quick removal, extending the work day for the time needed to remove the sensor. Thus, a need exists in the art for a multi-sonic sensor that addresses these deficiencies.
Therefore, an objective of the present invention is to provide a multi-sonic sensor which more accurately measures elevation and steering.
A further objective of the invention is to provide a multi-sonic sensor that more accurately measures temperature compensation.
A still further objective of the present invention is to provide a multi-sonic sensor that is capable of quick removal.
These and other objectives will be apparent to one of ordinary skill in the art based upon the following written description, drawings, and claims.